Apparatus for drawing sheet glass



June 23, 1931. -H. L., HALBACH I y 1,811,125

APPARATUS FOR DRAWING SHEET GLASS Filed April 4 1928 2 Sheetsfheet l.Egp 1. 0 j

June 23, 1931. l H. l.` HALBACH 1,811,125vr APPARATUS FOR DRAWING Ysaam@mss Filed April 4 192g .2 sheetspshee, v2

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Patented June 23, 1931 UNITED STATES PATENT OFFICE HOWARD L. HALBACH, OFCLARKSBURG, WEST VIRGINIA, .ASSIG'NOR TO PITTSBURGH PLATE GLASS COMPANY,A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR DRAWING SHEET GLASS Application filed April 4, 1928.SerialNo. 267,240.

The invention relates to apparatus for drawing sheet glass. lt. has forits primary object the provision of means for preventing the sheet beingdrawn from thinning along lines inward from the side edges of the sheetin the use of the Slingluif drawing machine, such as disclosed in theSlinglull' Patent No. 1,549,513. In the use of this apparatus, there isa tendency of the sheet to thin, as indicated at a in Fig. 4, whichshows a. horizontal section through the edge of a sheet produced o onthe Slingluff machine. This thinning of the sheet tends to increase thepercentage of breakage and requires that a wider margin of the edgeshall be trimmed off than would otherwise be the case. The presentinvention is designed to remedy this condition. One embodiment of theinvention is illustrated in the accompanying drawings, wherein:

Figure l is a vertical section on the line I-I of Fig. 3. Fig. 2 is ahorizontal section on the line II-II of Fig. 8. Fig. 3 is a. verticalsection on the line III-III of Fig. 1.

And Fig. 4 is an enlarged horizontal section through the edge of a sheetproduced on the Slingluf machine not employing the improvement to whichthe present invention relates.

Referring to the drawings, 1 is the end of a melting tank, preferably ofthe regenerator type; 2 is a drawing tank or kiln communi eating withthe melting tank; 3 is the lower end of a. drawing apparatus providedwith the pairs of driven rolls 4 4, 5-5, etc.; 6 is the draw barextending transversely of the bath beneath the line of generation of thesheet 7; and 8, 8 are coolers to which the invention particularlyrelates extending transversely of the bath on opposite sides of theglass sheet.

The coolers are similar so that a description of one will be sufficientfor both. They are made of cast or sheet metal with an inlet pipe 9 atone end and an outlet pipe 10 at the. other, such pipes being providedwith the valves 11 for regulating the flow. 'Ihese pipes preferahl)vconnect to the top of the cooler at its ends, as indicated in Fig. S andthe cooling fluid pursues the path indicated by the arrowsin thedrawings. In order to give additional thicknesses at the points a, a, atwhich points the sheet normally runs somewhat thinner, the projectingportions 12, 12 are provided on the cooler, such projecting portionshaving their faces lying closer to the glass than vthe surface of vthecooler intermediate such portions, so that the cooling ef-l fect uponthe sheet is greater adjacent the ends of such sheet. It has been foundthat the provision of these means thickens up the sheet at the thinportions a, a, so that the breakage is reduced and the sheet may bethereto, and provided opposite the marginal' portions of the sheet withenlargements whose faces also lie parallel to the sheet and closer tothe sheet than does the face of the cooler intermediate theenlargements, and means for circulating a cooling liquid through thecooler. o

In testimony whereof, I have hereunto subscribed my name this 30th dayof March, 1928.

HOWARD L. HALBACH.

